Low-tension strand-plying method and apparatus



g- 7 A. w. VIBBER 3,336,740

LOW-TENSION STRAND-PL YING METHOD AND APPARATUS Filed Oct. :51, 1966 4Sheets-Sheet l INVENTOR.

, Aug. 22, 1967 A. w VIBBER 3,336,740

LOW TENSION STRANDPLYING METHOD AND APPARATUS Filed Oct. 31, 1966 4Sheets-Sheet 2 is Q IN VENTOR.

, WMJJ Aug. 22, 1967 A. w. VIB BER 3,336,740

LOWTENSION STRAND-FLYING METHOD AND APPARATUS Filed Oct. 31, 1966 4Sheets-Sheet 3 I a 6 c a; 1 I m a) 1 jf United States Patent 3,336,740LOW-TENSION STRAND-FLYING METHOD AND APPARATUS Alfred W. Vibber, 560Riverside Drive, New York, N.Y. 10020 Filed Oct. 31, 1966, Ser. No.598,578 21 Claims. (Cl. 5758.86)

ABSTRACT OF THE DISCLOSURE A novel cord forming spindle of theskip-plying type, and a system having a plurality of such spindles andtaking up the cords directly from such spindles on a common beam. In thespindle of the invention a first, outer singles strand is rotated in theform of a loop or balloon about a source of a second, inner singlesstrand. The spindle incorporates a feeding means which engages the firststrand as it rotates in the loop or balloon and feeds it atsubstantially constant speed toward the point at which the two singlesstrands are plied together. The second, inner strand is fed undersubstantially constant tension to the plying point. The plied strand orcord is pulled away from the plying point under tension. The feedingmeans for the first, outer singles strand isolates loop or balloontension from the plying point, permitting the plying to be carried outat a desirably low tension, and permitting the cords thus formed by aplurality of such spindles to be taken up, if desired, directly from thespindles by a driven common take-up beam.

This application is a continuation-in-part of application Ser. No.531,914, filed Mar. 4, 1966, and of application Ser. No. 584,288, filedAug. 15, 1966, both now abandoned.

This invention relates to a method of and an apparatus for twisting and/or plying strands, and particularly relates to a method of and anapparatus for plying strands together by rotating a strand about asource of supply of another strand, and plying the strands togetherbeyond such source of the other strand.

This invention relates to an improvement upon the method and apparatusdisclosed and claimed in applicants prior Patent No. 3,153,893, datedOct. 27, 1964. The present invention provides a more positive means forthe control of the feeding of the outer ballooned strand to the plyingpoint, and thus provides for the production of a two-strand cord whichis particularly characterized by its symmetry of construction and thusits ability to distribute tensional forces imposed thereon equallybetween the two strands which form the cord.

The above and further objects and novel features of the invention willmore fully appear from the following description when the same is readin connection with the accompanying drawings. It is to be expresslyunderstood, however, that the drawings are for the purpose ofillustration only, and are not intended as a definition of the limits ofthe invention.

In the drawings, wherein like reference characters refer to like partsthroughout the several views,

FIG. 1 is a fragmentary view in side elevation of a first disclosedembodiment of .spindle for plying strands together to form a cord inaccordance with the present invention;

FIG. 2 is a fragmentary view partially in side elevation and partiallyin vertical section of the balloon control means employed with thespindle of FIG. 1;

FIG. 3 is a fragmentary view on an enlarged scale of the inner constantspeed capstan and of the drive therefor, such capstan feeding the outerballooned strand toward the plying point of the spindle;

FIG. 4 is a view in side elevation of a second embodiment of plyingspindle in accordance with the invention;

5 is a view in side elevation of the auxiliary flyer employed with thespindle of FIG. 4;

FIG. 6 is a view in vertical section through the auxiliary flyeremployed as an element of the spindle of FIG. 4 the section being takenalong the line 66 of FIG. 5;

FIG. 7 is a view in horizontal section through the auxiliary flyer, thesection being taken along the broken section line 7-7 of FIG. 5;

FIG. 8 is a somewhat schematic view in perspective of a novel system forsimultaneously winding plied yarns produced by a plurality of spindlesin accordance with the invention onto a multiple end beam;

FIG. 9 is an end view of the plied yarn take-up of the system of FIG. 8;

FIG. 10 is a plan view of the plied yarn take-up of FIG. 8;

FIG. 11 is a schematic view in side elevation of one of a plurality oftension devices which may be added to the beam winder of FIGS. 8, 9, and10 to provide increased winding tensions in the cords; and

FIG. 12 is a schematic view of a ply-wrapping spindle of generally thesame construction as that of the first disclosed embodiment herein, butwith a constant tension take-up device for the cord substituted for theconstant speed cord take-up device of the first embodiment.

As apparent from the above, three embodiments of plying spindle areshown in the accompanying drawings: The first embodiment is shown inFIGS. 1, 2, and 3, wherein the plying point X is located generallywithin the main flyer of the spindle and generally at a point on theaxis thereof. The second embodiment is shown in FIGS. 4, 5, and 6; insuch second embodiment, the plying point is a generally floating one,that is, it is free to rise and fall within limits and has appreciablefreedom to center itself with respect to the axis of the rotatingballoon or loop. In such first two embodiments the plied strand or cordis withdrawn at substantially constant speed under tension from theplying point. In FIG. 12 there is schematically illustrated a thirdembodiment of plying spindle wherein the plied strand or cord iswithdrawn from the plying point under constant tension.

Turning now to the drawings, the spindle of FIGS. 1, 2, and 3 issomewhat the same as that of applicants prior Patent No. 3,153,893,above referred to, with the exception that the capstan which feds theouter ballooned strand positively toward the plying point is located onthe flyer immediately adjacent the plying point rather than beinglocated in advance of the entry of such strand into the balloon. Theballoon is controlled as to size by means which has no appreciableeffect upon the plying action of the two strands but merely keeps theballoon within practical controlled limits. The same referencecharacters are used in the spindle of FIGS. 1, 2, and 3 as in the firstdisclosed embodiment of spindle in Patent No. 3,153,893, with theexception of those applied to the capstan which feeds the first or outerballooned strand to the plying point, and those applied to the means forcontrolling the diameter of the balloon.

Thus in FIG. 1 there is shown a spindle generally designated 10 whichhas a main vertical driven hollow shaft 11. Such spindle is mounted upona frame generally designated 12 in which the shaft '11 is suitablyjournalled in a housing 16, such shaft being driven by means of a belt14 entrained over a pulley 15 secured to the shaft 14, such belt beingconnected to a suitable driving means (not shown). Mounted upon theshaft 11 is a flyer 19 which rotates with the shaft 11, and above theflyer and held from rotation therewith with cooperating magnets 20 and21 there is a sub-frame 17. Upon such sub-frame there is mounted asupport 22 within a cage 23, the support 22 carrying an inner package 24which supplies an inner strand b to the plying point X. Such innerstrand b is fed from the package 24 downwardly to an idle tensioningmeans generally designated 26, which may be the same as that similarlydesignated in applicants prior Patent No. 3,153,893. The tensioningdevice 26 includes a pair of staggered idle rollers 27 and 29 to whichthe strand 1; is directed by the guide roll 25. An adjustable leafspring 30 is mounted to cooperate with the roller 29. From thetensioning device 26 strand b is delivered over a guide roll set 31 andthence to a canted roller 32 and thence downwardly into the verticalbore through the hollow shaft 11.

The outer ballooned strand a is supplied from a package 34 which ismounted upon a spindle 35, the strand progressing upwardly partiallyabout a guide pulley 39 and thence to a further guide pulley 41 andupwardly to a pulley 42. From the pulley 42 the strand a travels to afurther guide pulley 44 on an overarm 45, and thence to an apex guidedevice generally designated 49. Device 49 includes means whereby thespeed of feeding of the strand a into the balloon is governed by balloondiameter detecting means, whereby to maintain the balloon within theballoon diameter within predetermined desired limits. From the apexguiding and balloon controlling means 49, which will be describedhereinafter, the strand a issues into the balloon generally designated50 and travels downwardly through the rotating balloon to the entranceend 51 of a generally radial passage 37 in the fiyer 19. From suchentrance 51 the strand a travels generally radially inwardly to theplying point X where it meets the inner strand [2 and is pliedtherewith. The resulting cord c travels downwardly through the hollowshaft 11 to an idle guiding means 52 and thence upwardly to a constantspeed capstan 54 which withdraws the cord c at constant speed from theplying point X. The capstan 54 includes a roller 55 which is driven intimed relation with the shaft 11 and an opposing idle pulley 56, thecord c being wrapped several times about the opposing rollers 55 and 56.In order to maintain a substantially fixed driving relationship betweenthe capstan 54 and the cord 0, there is employed a spring biased idleroll 57 which pinches the multiple runs of the cord 0 between it and theroll 55. From the capstan 54 the cord c travels downwardly to a take-upmeans which is shown generally as being made up of a bobbin 59 whichlies upon driven rollers 60 so as to be fricti-onally driven thereby.

The apex guide and balloon controlling device in the spindle of FIG. 1,which is shown more particularly in some of its details in FIG. 2, isgenerally similar to that shown in FIG. of applicants prior Patent No.2,871,648. Such device includes an idle retarded capstan set 62 to whichthe outer strand a travels from the guide pulley 44. After travelling anumber of times about two opposed rollers 72 and 73 making up capstanset 62, the strand a travels downwardly in a vertical run through theapex guide proper of device 49 from which it issues into the balloon 50.Rollers 72 and 73 are of the same effective diameter, and are geared torotate in synchronism in the same direction by gears 79 on such rollers,such gears meshing with an intermediate pinion 80.

The construction of device 49, its connection to the balloon controllingbell 64, and the manner of interaction between device 49 and capstan 62are illustrated in FIG. 2. As there shown, a hollow spindle 65 disposedcoaxially of and a fixed distance from the main spindle shaft 11 isrotatably mounted on ball bearings in an upper fixed frame partfragmentarily shown at 66. Spindle 65 carries at its lower end inwardlythereof a central guiding eye or apex guide 67 for the free end of theballoon. The lower end of spindle 65 also serves as the support for bell64. The upper end of the bell is provided with a central hole whichrecives the lower externally threaded end of the spindle, as shown. Thebell may be integrally connected to the spindle, or may be clamped onthe spindle, so as to be non-rotatable with respect thereto, by havingits central upper portion gripped between an outwardly directed flangeon the spindle and a nut screwed onto the spindle.

The spindle 65, and thus the bell 64, are yieldingly turned in thedirection opposite from the direction of rotation of balloon 50 by acoil spring 69 disposed around a spindle 65 above frame part 66. One endof spring 69 is secured to frame part 66, and the other end is securedto a collar 70 adjustably held in a selected position around the axis ofspindle 65 by a thumb screw as shown. By loosening the thumb screw andturning collar 70 around the spindle, the spring 69 may be wound toimpose a desired initial torque on the spindle 65.

The upper end of spindle 65 is internally threaded. An inner sleeveportion of a brake-applying member 71 is externally threaded, and mateswith the internal threads on spindle 65. The lower end of the sleeve onmember 71 has an external cylindrical zone which slidingly engages theinner cylindrical surface of spindle 65 below the threads thereon, so asto aid in guiding such sleeve. The sleeve has a central axial bore whichreceives strand a therethrough in its passage downwardly from the lowerroll of capstan 62 to the apex guide 67.

The sleeve on member 71 has integral therewith an upper outwardlydirected flange which carries a downwardly directed short outer sleevewhich surrounds and is spaced radially outwardly from the upper end ofspindle 65. The outer surface of such short outer sleeve is verticallyslidingly received in a bore in an upper fixed frame part 74, which islocated spaced above frame part 66. The above described sleeves areprevented from rotation by the engagement of splines on one sleeve withgrooves in the sidewall of the bore in frame part 74. The threads onspindle 65 and on the sleeve which is threaded thereinto are made ofsuch hand that spindle 65 is turned in the direction of rotation of theballoon 50 by engagement of the rim 75 of bell '64 by the balloon, themember 71 rises, and when spring 69 turns the spindle 65 in the reversedirection the member 71 descends. Descent of member 71 is stopped byengagement of an adjustable stop stud 76 threaded into a radial arm onmember 71. The lower end of stud 76 engages frame part 74 when member 71fully descends. When the balloon 50 engages the rim 75 of bell 64 withsufiicient force to rotate the spindle 65 to raise member 71, graduallycontracts as a result of the action of member 71, spring 69 turnsspindle 65 in the reverse direction, causing member 71 to descend.

Member 71 carries on its upper end an upwardly open vertical walledcavity carrying a brake shoe 77 vertically reciprocable therein. Thebrake shoe is urged upwardly in the cavity by a relatively stiff coilcompression spring acting between a shoulder on the brake shoe and thebottom of the cavity. Brake shoe 77 engages a brake drum affixed to theshaft carrying roll 72 of capstan 62. The parts of mechanism 49,including brake shoe 77, the spring backing up the brake shoe, and thebrake drum are so dimensioned that in the normal operation of thespindle the strand a in the balloon 50 engages the rim 75 of the bell64. It will he obvious that upon an increase in diameter of the balloonthe brake shoe 77 will engage the brake drum more forcibly, therebydecreasing the speed of capstan 62 and causing strand a to be fed moreslowly into the balloon. Thereupon the diameter of the balloon decreasesso that the balloon eventually ceases to contact bell 64 so strongly,spindle 65 turns in a direction opposite the direction of rotation ofthe balloon, member 71 descends, and capstan 62 again resumes itspredetermined desired speed to maintain the balloon with the desireddiameter. It will be obvious that the reverse corrective action takesplace when the balloon contracts unduly in diameter.

The means for driving the constant speed capstan which is mounted uponthe fiyer of the spindle is generally similar to that shown in FIGS. 4and 5 of applicants prior Patent No. Re. 24,483, with the exception thatonly one capstan roll is shown as being employed on the flyer. Thus theouter ballooned strand a in leaving the balloon 50 travels inwardlythrough the outer end 51 of the radial passage 37 in the flyer andthence to the capstan roll 81 which is journalled in the hub of theflyer 19 transverse to the axis thereto and spaced somewhat radiallyfrom such axis. The capstan roll 81 is driven in synchronism with themain shaft 11 of the spindle, and thus the flyer 19. The means for thusdriving the capstan 81 includes a sleeve 82 which extends upwardlycoaxially within the shaft 11, such sleeve being secured to the frame 12by means of angular brackets 84 secured between the bottom of the sleeveand the frame 12. The upper end of the sleeve 82 carries a worm 85 whichmeshes with a Worm gear 86 journalled in the hub of the flyer, the wormgear in turn being connected to the capstan roll 81 by meshing pinionsconnected respectively to the worm gear 86 and capstan roll 81. It willthus be apparent that upon turning of the shaft 11 and the flyer 19 thecapstan roll 81 is turned in synchronism therewith. Strand a is wrappedseveral times about capstan roll 81 so as to have substantiallynon-slipping engagement therewith. The capstan roll 81 thus feeds theouter ballooned strand a forwardly at constant speed to the plying pointX of the spindle.

As above noted, the spindle and method of plying of the presentinvention divorce the control of the balloon and tension variations insuch balloon from the action of the two strands a and b as they arebeing plied together to form cord c at the plying point X. Thus the cordformed by the spindle is particularly characterized by its symmetry,that is, the uniformity in the length of the two strands a and b in thecord c. This follows from the fact that the tension imposed upon thecord by the take-up capstan 54 tends to be equally divided between thetwo strands a and b immediately in advance of the plying point X. Itshould be noted at this point that the capstan 81 which forwards thestrand a to the plying point is driven at a somewhat higher surfacespeed than that of the takeup capstan 54. Typical values in a spindlesuch as described would be a surface speed of 114" per unit of time forthe capstan 81 and a surface speed of 100" per same unit of time for thetake-up capstan 54. With such arrangement, if it were not for thefeeding forward of the inner strand b to the plying point X, the capstan77 would always deliver an excess length of the outer strand a to thetake-up capstan 54. The strand b, however, supplies, in effect, an addedfactor which takes up the excess length of strand a delivered to theplying point by winding it about the strand a and thus absorbing it intothe cord. There is thus never any question of exerting an excess tensionupon the formed cord 0 or the strand a by the interaction of the take-upcapstan 54 and the singles capstan 81.

As above noted, the tension in the cord 0 between the take-up capstan 54and the plying point tends to be equally divided between the strand aand b immediately in advance of the plying point. If during operation ofthe spindle the tension in the outer balloon strand a should riseunduly, it tends to become the core so that less of such strand isabsorbed into the cord and more of strand b is absorbed thereinto. As aresult, the tension in strand a decreases and tends to equal thatimposed upon the strand b by the constant tension-imposing device 26.The converse is true when the tension in strand a between capstan 77 andthe plying point decreases unduly: The strand b approaching the plyingpoint then tends to become the core, more of strand a than of strand bis absorbed into the cord, and the tensions in strands a and bapproaching the plying point are rapidly equalized so that equal lengthsof the two strands are absorbed into the cord.

The second embodiment of apparatus and method in accordance with theinvention, which is shown in FIGS. 47, inclusive, employs an apparatuswherein the plying point floats to a substantial extent about the axisof the main shaft of the spindle and wherein the diameter and thustension in the ballooned strand is controlled by a storage wheel.Generally the apparatus is similar to that shown in Klein Patent No.2,811,012 with the exception that instead of positively synchronizedcapstans on the auxiliary flyer the one of such capstans engaging theouter, ballooned strand is positively driven but the other is idle andserves to guide the inner strand to the plying point. Such inner strandis subjected to a predetermined constant tension by a tension deviceassociated with the supply package for the inner strand.

The spindle of the embodiment of FIGS. 4, 5, 6, and 7 is designatedgenerally by the reference character 100. As above noted, such apparatuscorresponds generally to that of Klein Patent No. 2,811,012 with theexceptions to be noted below. Such spindle has a main shaft 103 which isdriven by a belt 101 generally indicated, such shaft having afiixed androtatable therewith a flyer 102 in which there is incorporated as anintegral part thereof a storage wheel 104. A first strand a fed from anouter package 105 is led past an idle constant tension imposing device107 upwardly into the bore of the shaft 103 and thence outwardly to theouter surface of the storage wheel 104. From such storage wheel thestrand a issues into a rotating loop or balloon 109, the diameter ofwhich is controlled by the storage wheel 104 in a well-known manner.

The strand a adjacent the upper end of the balloon 109 is wrapped one ormore times in non-slipping engagement about a capstan roll 110 whichforms a part of an idle auxiliary flyer 111 constructed generally inaccordance with that of the above noted Klein Patent No. 2,811,- 012.There is this important difierence, however, between the apparatus ofthe present invention and that of Klein: The opposite roll 112 of theauxiliary flyer 111 is idle and serves only to guide the inner strand bto the plying point X in a manner which is symmetrical to and oppositefrom that of the outer strand a. The auxiliary flyer 111 is mounted upona hollow shaft 114 which is journalled in a housing 113 supported upon abracket 115, as shown. As will be apparent hereinafter, during therotation of the auxiliary flyer 111, the capstan 110 is driven insynchronism with the rotation of the balloon 109 and thus of the flyer102 by a gear mechanism which is more particularly shown in FIGS. 5, 6,and 7. The opposite roll 112 of the auxiliary flyer 111 is idle, beingdriven only by the passage of the inner strand b thereover.

An inner supply package 116 is non-rotatably mounted through suitablebearings upon the main shaft 103 and the flyer 102 of the spindle, thestrand b from package 116 passing through a constant tension device 117which is non-rotatably mounted upon the spindle. From the tension device117, the strand b passes to a guide 119 which is mounted on the upperend of the enlarged head 131 of the shaft 114 for the auxiliary flyer111. The above-mentioned driven capstan 110 and the idle capstan 112 arerotatably mounted upon stub shafts 132 and 134, respectively, suchshafts being disposed in the same vertical axial plane and projecting inopposite directions at equal shallow angles with respect to thehorizontal. The rolls 110 and 112, as well as the other parts of theauxiliary flyer to be described, are so constructed and arranged thatthe auxiliary flyer is in dynamic balance.

As in the above Klein patent, the auxiliary flyer 111 is driven by andin timed relationship with the balloon 109. Such driving is effected byhaving the strand a of the balloon 109 pass through a pigtail 122 whichis formed in the radially outer end of a wire arm 123 afiixed to theauxiliary flyer 111. During the-operation of the de: vice, the capstans110 and 112 rotate as a whole with the auxiliary flyer 111 insynchronism with the shaft 103 and the flyer 102. The inner strand b isdelivered to the plying point X under a constant tension imposed thereonby the tension device 117. The driven capstan 110, however, is causedtorotate at a constant linear speed which somewhat exceeds the constantlinear speed of the taking up of the plied cord by mechanism to bedescribed.

Turning to FIGS. 5, 6, and 7, the construction and manner of operationof the mechanism for rotating the capstan 110 at constant speed will beapparent. At its base the head 131 of the shaft 114 is extendedforwardly (FIGS. and 7) in two laterally spaced similar L-shaped arms135 and 136, and is extended rearwardly in a balancing portion 142. Aworm 137 of shallow pitch is fixedly disposed on the housing 113adjacent the upper end of the latter. A worn gear 139 which meshes withthe worm 137 is disposed between the depending portions of the arms 135and 136 which journal the shaft 140 upon which the worm gear 139 ismounted in suitable bearings. The shaft 140 projects laterally outwardlyof the arm 135 and is provided on its outer end with a bevel spiral gear141 which is fixedly connected thereto. The gear 141 meshes with a gear121 which is integrally connected to the capstan 110. It will beapparent that as the auxiliary fiyer 111 rotates about its vertical axisit carries the worm gear 139 with it, the worm gear turning as itrotates about the worm 137. Such rotation is transmitted by the shaft140 and the meshing spiral gears 141 and 121 to the capstan 110. By asuitable choice of pitch and diameters of the worm and worm gear 137 and139, respectively, and of the diameters of the meshing spiral gears 121and 141, the capstan 110 will rotate at such constant linear speed as toproduce a cord having the required number of twists per inch.

Above the plying point X there is an apex guide in the form of a roll124 over which the plied cord 0 passes. The plying point X, as can beseen, floats to a limited degree in that its location relative to theapex guide 124, as well as its radial distance from the axis of theballoon 109, can change as required. The apex guide 124 forms a part ofa constant speed cord take-up device wherein the roll 124 is driven atconstant speed, such roll cooperating wtih a large, idle roll 125 whichis parallel thereto and spaced therefrom. The cord 0 after passinginitialy partially around roll 124i travels in repeated laterally spacedruns 126 around rolls 125 and 124, finally being taken off in a run 127which extends to a take-up bobbin 129. Such bobbin is dirven in aconventional manner by being mounted upon and frictionaly driven by aconstant speed driving roller 130.

Many of the advantages of the present invention will be apparent fromthe above. However, it would be well to summarize here the novelfunctions of the apparatus of the invention and the improved resultsflowing therefrom.

(1) The constant speed singles-feeding capstan 81 of the first describedembodiment and 110 of the second embodiment isolate the tension of theballoon from the plying or cording point.

(2) The portion of the outer, ballooned singles strand between capstans81 and 110 and the respective plying or cording points is quite short ineach case, and such portion lies close to the axis of rotation of suchsingles. Consequently the contrifugal force and the air resistance inthe second embodiment operative upon such portion of the outer singlesstrand are small. It will be understood that such portion of the outersingles strand may be made substantially shorter than those shown in thedrawings, as by locating the capstan 81 of the first embodiment closerto the axis of the spindle, or by appropriate changes in diameter ofsuch capstan 81, and by similar changes in the roll couple, includingthe capstan 110 of the second embodiment.

As consequences of conditions (1) and (2), the plying of the two strandscan be carried out under a low tension if desired, the tension imposedon the inner singles strand by tension means 17 in the first embodimentand the tension means 117 in the second embodiment determining theplying tension. With low tension plying the resulting cord hasproperties of elongation under load which are fully as good as those ofcord produced by the ring twisting process. Such plying tension may beadjusted within a wide range by appropriately adjusting the tensionmeans 17, 117. Further, because of the short length of the portion ofthe outer, ballooned singles strand between the capstans 81 and and theplying points in the respective embodiments, weight variations per unitlength in the outer ballooned strand, as by changes in the moisturecontent of such strand, or even in the denier of the strand, have littleeffect upon the plying of the strands at the plying or cording point.Thus the apparatus and method of the invention may be employedsuccessfully to ply even non-premium quality strands and/ or strandswherein the moisture content is not carefuly controlled.

Because of the isolation of the plying or cording point from the tensionof the outer strand in the balloon, the spindle can be run faster thanprior spindles. The highest speed at which the spindle can be rundepends, of course, upon a number of factors, including the capacity ofthe bearings employed to run at sustained high speeds, the powerrequirements of the spindle, the maximum tension to which it isadvisable to subject the outer strand in the balloon, and the length oftime which is required to relax the strand from its high tension, andpossibly stretched condition in the balloon to its low tension,virtually unstretched condition under which it is plied with the innerstrand.

The transition from the high tension condition of the outer strand, inthe balloon, to the low tension condition, under which it is combinedwith the inner strand at the plying point, is effected gradually in bothdisclosed embodiments of the apparatus. The outer strand enters upon therespective singles capstan 81, 110 from the balloon under the hightension of the balloon. During the travel of such strand through theseveral wraps or turns thereof about the capstan, the strandprogressively creeps to a small extent upon the surface of the capstanas the strand is subjected to lower and lower tension. This isparticularly true of strands made of material such as nylon whichstretches appreciably under substantial tension. Thus even at high speedrotation of the spindle, and accordingly high speeds of travel of thesingles strands to the plying point, there is afforded sufficient timefor the outer, ballooned strand to adjust its length suitably before itreaches the plying point so that the resulting cord is of balancedconstruction. It is to be understood that, although the outer strand hasbeen described as creeping upon the surface of capstan 81, 110, sucheffect is actually very small. Also, such creepage is virtually constantunder a given set of conditions, and thus capstans 81 and 110 feed theouter ballooned strand at a constant speed, such speed being the properone to supply the required length of such outer singles strand to theplying point.

With regard to the embodiment of the spindle of FIGS. l-3, inclusive, itis desired to point out that the balloon controlling device 49 may bereplaced, if desired, by other known balloon controlling devices whichmaintain the balloon diameter within close limits. Also, if the spacebetween successive spindles in a frame is not critical, the ballooncontrolling portion of device 49 may be replaced by a simple, constanttension-imposing means comparable to the device 107 of the seconddescribed embodiment. In this case, the balloon itself isself-compensating, the balloon expanding and contracting within limitsas required to maintain the tension of the strand therein equal to thatimposed by the above described constant tension-imposing deviceoperative upon the outer singles strand prior to its entry into theballoon.

Although in both of the preferred embodiments illustrated herein anddescribed above the plied strand or cord is pulled away from the plyingpoint at substantially constant speed, a substantial part of theadvantages of the present invention are realized when the plied strandor cord is merely fed away from the plying point under ten:

sion. Preferably, for reasons of uniformity of the plied strand, in thislast embodiment the tension applied to the plied strand by the feedingmeans 200 therefor is uniform or constant. Such feeding means 200, forpulling the plied strand away from the plying point under tension, may,for example, be one such as that employed for the same purpose inClarkson Patent No. 2,503,242 or Clarkson Patent No. 2,729,051, both ofwhich subject the plied strand to a uniform tension. When the pliedstrand is to be symmetrical, that is, to contain substantially equallengths of the two singles strands a and b, the tension Tc which thefeeding means for the plied strand imposes on the plied strand 0 isslightly greater than twice the tension Tc imposed on the inner,non-ballooned singles strand b by the constant tension imposing meanswhich engages it. The small amount by which tension T0 exceeds twice thetension Tc; is necessary in such case to overcome the friction in thestrand system and to provide the force for pulling the plied strand fromthe plying point. The remainder, T0 of the constant tension T0 imposedon the plied strand is, of course, sustained by the final run 1 of theouter, ballooned singles strand which extends between the constant speedcapstan, which engages and feeds such strand from its balloon or loop,and the plying point.

In FIG. 12, the outer strand a is fed into the outer end of the balloon50 by a balloon control device 49, and is fed from the inner end of theballoon 50 by a constant speed capstan 84 on the fiyer 19, both as inthe embodiment of FIGS. 1-3, inclusive. The inner strand b is engaged bya constant tension retarding device 26 also as in FIGS. 1-3, inclusive.

It will be seen that in the spindle of FIG. 12:

T0 substantially equals T0 Tc substantially equals Tc +Tc and T0substantially equals 2Tc and substantially equals As a result, the pliedstrand or cord produced by the apparatus of FIG. 12 is characterized byits high degree of symmetry. As in the above two Clarkson patents, thecord is finally wound on a package 59, as in the embodiment of FIGS.1-3, inclusive. The means for rotating and controlling the package 59maybe that of either of such Clarkson patents; its construction is suchthat its operation does not disturb the constant tension with which thetake-up device pulls the plied strand away from the plying point P.

It is to be understood, however, that in some instances it may not bedesired that the plied strand be uniform, and/or it may not be desiredthat the plied strand be symmetrical as regards the lengths of the twosingles strands which it contains. In such cases, (A) the tension whichthe feeding means for the plied strand imposes thereon need not beuniform, or may deliberately be made non-uniform, and (B) the tensionimposed upon the plied strand by its feeding means need not be twice thetension imposed upon the inner, non-ballooned singles strand by theconstant tension imposing means which engages it; both of conditions Aand B may be present in some manners of practice of the invention. Incondition B, to produce a plied strand without regard to its symmetry,the tension imposed on the plied strand by its feeding means needs onlysomewhat to exceed the tension imposed on the inner, non-balloonedsingles strand by its constant tensioning means; the tension of theplied strand can be varied from such minimum value to and substantiallyabove twice the tension imposed on the inner singles strand by itstensioning means. As is well known, in the making by the ply-wrappingprocess of a two-ply strand of two substantially identical singlesstrands, when one singles strand is subjected to a greater tension atthe plying -or cording point than the other, the one singles strandtends to become the core and the other singles strand tends to wrapabout it.

The last described embodiment of the invention, Wherein the plied strandis merely fed away from the plying point under tension (under uniformtension when a uni form plied strand is desired), has the same principaladvantages as those set forth above in connection with the twoembodiments illustrated herein and first described above. The constantspeed capstan for feeding the outer, ballooned singles strand from theballoon or loop isolates the tension, and any variations therein, of theballoon or loop from the cording or plying point. The run of the outersingles strand from such constant speed capstan to the plying point maybe made short, is located near, and at its inner end substantially on,the axis of the loop, and thus is subjected to a very small centrifugalforce. The tension to which such run of the outer singles strand issubjected by reason of its own manner of travel and feeding is small. Byfar the predominant part of the tension to which such run of the outersingles strand is subjected comes from the tension imposed upon it bythe tension in the portion of the inner singles strand approaching theplying point and the tension in the plied strand or cord leaving theplying point. As pointed out above, both such latter tensions may bemade to be relatively low, with a consequent improvement in theproperties of elongation under load of the plied strand.

FIGS. 8, 9 and 10 illustrate somewhat schematically a novel system forwinding plied yarns or cords produced by a plurality of spindles made inaccordance with the invention onto a multiple beam end. Such system, byreason of the use of spindles of the invention, permits the cords to bewound directly, and at low tension, upon the beam, without the necessityof a take-up capstan device, as is required between the spindles and themultiple end beam in prior systems of the same general type.

As shown in FIG. 8, a plurality (only six shown) of similar alignedply-wrapping spindles, which are generally similar to that of FIG. 4herein, feed the cords 0 formed thereby upwardly to individual guiderollers 151, and thence horizontally to a multiple end beam windingdevice, generally designated 152. It will be understood that in themaking of fabric from the cords, as many spindles may be employed as arenecessary to form the desired warp-like sheet. The take-up beam, withthe warplike sheet wound thereon, is ready for use directly at a loomfor forming fabric, such as tire cord fabric.

Each of the spindles 150 has a main hollow spindle shaft 214 which isrotated by a belt 215 driven by a power source (not shown). A first,outer singles strand a is fed upwardly into the lower end of shaft 214after passing through a strand guiding and tensioning means which is notshown in FIG. 8. The strand a rises in shaft 214 to pass radiallyoutwardly thereof through a passage 216 in the side wall of the shaft,the strand then being wrapped to a varying degree about a strand storagewheel 217. From the storage wheel the strand a passes into a balloon orrotating loop 219 which revolves about a stationary housing 220. Withinthe housing there is supported a strand package 221 for a second, innersingles strand b. Strand b travels upwardly from package 221 to passthrough an adjustable strand tensioning device 222, which, whenadjusted, imposes a predetermined constant tension on strand b as itpasses therethrough.

The strand b meets the strand a at a plying point not specificallyshown, which lies generally on the axis of the spindle shaft 214, suchplying point lying above the location at which the rotating strand a isengaged and synchronously metered by a capstan roll 245 which is mountedon an auxiliary fiyer 224 which is rotatably mounted coaxially of thespindle shaft 214 on a suitable fixed support 225. The auxiliary fiyer224 has a body 240 of downwardly open conical shape, as shown. The fiyer224 is driven to rotate about its axis by, and at the same speed as, theballon 219. The capstan roll 245 is driven to rotate about its own axisto feed the strand a to the plying point at the proper speed, in excessof the speed of withdrawal of the resulting plied strand or cord 0, bymeans not here specifically shOWn.

Such driving means may, for example, include a central fixed hollowshaft on support 225 and disposed coaxial of spindle shaft 214, saidfixed hollow shaft conducting the cord away from the plying point. Theauxiliary flyer 224 is rotatably mounted on suitable hearings on anintermediate portion of said fixed hollow shaft, the lower end of whichprojects into the upper end of the conical flyer body 240. A pinioncoaxial of such shaft is aflixed to the lower end thereof within theupper end of the body 246'. A suitable speed reducing gear train, whichmay include a series of meshing gears, is mounted on the flyer body 240within the cavity therein, and extends from the pinion on the lower endof the hollow shaft to the capstan roll 245. It will be apparent that,as the auxiliary flyer is rotated by and at the same speed as theballoon, the strand 0 when suitably Wrapped about the surface of thecapstan roll 245 will be fed to the plying point at an accurate,predetermined desired speed. As with the similar Singles feeding capstanrolls of the embodiments of FIGS. 1-7, incl., herein, the capstan roll245 isolates the tension of the balloon from that existing in the run ofstrand a between the capstan roll 245 and the plying point. Not onlydoes this permit the plying of the strands to be carried out under adesirable low tension, but it permits the speed of feeding of the cord 0to be varied slightly, as may be required by the apparatus of FIGS.8-11, incl., in a manner now to be described.

The cords c are gathered into the relationship which they are to have onthe beam as they are led thereto through spaced guides 154 on a fixedguide board 155.

The beam winding device 152, which is shown more particularly in FIGS. 9and 10, has a carriage 156 with a horizontal bed 157, the carriage beingsupported for reciprocation transversely of the paths of the cordsapproaching device 152. In the embodiment shown, the carriage 156 issupported on a fixed table 159 through the medium of a plurality of setsof rollers 160, of which one set is shown in FIG. 9, distributed overthe area of the carriage. The carriage 156 has upstanding parallel walls161 at its opposite ends, such walls journalling horizontal spacedparallel rubber-covered rolls 162 and 164 therebetween. The roll 162, inthis instance, is driven by an axially fixed shaft 165, and roll 164 isidle, although if desired both rolls may be driven. To permit the roll162 to reciprocate axially relative to shaft 165, there is provided asplined coupling 166 between shaft 165 and the shaft 167 of the roll162.

The rolls 162 and 164 support the flanged multiple end beam 169 uponwhich the cords c are wound, the rolls being received between theflanges of the beam, as shown. The driving roll 162, which is driven ata constant peripheral speed, drives the cord-receiving surface of thebeam 169 at the same speed regardless of the diameter of the beam.Non-slipping contact between the cordreceiving surface of the beam andthe surface of driving roll 162 is maintained by a hold-down devicehaving arms 170 secured to a horizontal rock shaft 171 extending throughthe end walls 161 of the carriage 156. The forward ends of the arms 170are provided with semi-cylindrical seats 172 which receive and partiallyjournal stub shafts 174 which extend from the opposite ends of the beam169 coaxially thereof. The arms 170 are urged downwardly to thrust thebeam against roll 162 by double acting reciprocable fluid motors 175which are pivotally mounted on the bed of the carriage 156. Motors 175have pistons and piston rods, the latter being pivotally connected to across rod 176 extending between the arms 170 intermediate their lengths.The introduction of fluid under pressure to motors 175 through upperconduits 177 thrusts arms 170 downwardly; such arms are elevated byexhausting fluid from conduits 177 and introducing it under pressureinto the lower conduits 179 of the motors.

The carriage 156, and thus the beam 169 and its supporting and drivingrolls 162, 164, are reciprocated lengthwise of the beam so as to layeach of the cords c in crisscross manner upon its zone of the beam. Itwill be apparent that by reason of the reciprocation of the beam 169rather than the plied strand guide board, the lengths of the path oftravel of the cords c from their spindles to the beam 169 remainsconstant at all times. The reciprocating stroke of the beam 169 may be,for example, a small distance which is no greater than twice the spacingbetween successive cords in the warp-like sheet. The carriage may bereciprocated in a number of ways, of which one is shown in FIG. 10. Asthere shown, a rigid member 180 extends from one end of the carriage156; such member 180 carries an upstanding rounded pin 181 at its outerend. Pin 181, which functions as a cam follower, is accurately receivedwithin the groove or cam track 182 of a traversing earn 184 which isfixed to a driving shaft 185. It will be apparent that with the properconfiguration of cam track 182, and predetermined speeds of rotation ofshafts 165 and 185, the device 152 will wind each cord 0 upon the beam169 at an accurately maintained constant speed which is correlated withand its somewhat less than the surface speed of the constant speedsingles feeding capstans of the spindles 150. Thus, in accordance withthe above mentioned example, the speed of winding of the cords on thebeam may be per unit of time when the surface speed of the singlesfeeding capstans of the spindles is 114 per same unit of time.

Because of the low tensions under which the cords c are formed anddelivered by the spindles 150, there is not required any take-up deviceother than the multiple end beam itself. The ability to coil a pluralityof cord 0 upon a common multiple end beam without the use of any othertake-up means arises from the self-compensating characteristics of thespindles 150.

The spindles have an auxiliary flyer 224 which carries a singles feedingcapstan 245 which is driven at a constant surface speed (114, forexample), when the predetermined speed of coiling of the cords c on thebeam 169 is 100. Under such conditions, the cord 0 is symmetrical, thetwo singles strands approaching the plying point are each subjected tothe same tension, that imposed by the fixed tension device engaging theinner singles strand, and the cord 0 is subjected to twice that tension.If a condition should arise, such as a slight irregularity of the outersurface of the wound cord on its zone of the beam 169, whereby the speedof take-up of such cord should momentarily increase, the spindlesupplying such cord automatically adjusts to supply the requisite lengthof cord to the beam. With the increase in the speed of pulling of thecord from the spindles, the tension in the portion of the outer,ballooned singles between its constant speed capstan and the plyingpoint increases. Thus more of the inner singles strand than of the outersingles strand is absorbed by the cord, and the effective length of thecord increases. Should the speed of takeup of the cord momentarilydecrease, the tension in the portion of the outer singles strand betweenits constant speed capstan and the plying point decreases. Now more ofthe outer singles strand than of the inner singles strand is absorbed bythe cord, and the effective length of the cord decreases. It should beunderstood that the described deviations of the cord from the desiredsymmetrical or balanced condition thereof are small, and with properdesign need be no more than those encountered in premium cord plied byoptimum ring twisting practice, or in cord plied by prior ply-wrappingapparatus wherein the balloon is controlled at least in part bydeliberately unbalancing the cord produced.

In many case, the desired low tension under which the singles strandsare plied is also ideal for winding the cord on a beam. If it should bedesired, however, to wind the cords on a beam under a higher tensionthan that employed in the plying operation, the take-up device 152 maybe supplemented by a plurality of tension devices 186, shown in FIG. 11,each of devices 186 engaging its respective cord at a location inadvance of the beam winder 152. Tension device 186 includes two fixed,nonrotatable bodies 187, 189, under and over which, respectively, thecord 0 passes, and a rotatable guide roll under which the cord passes. Aleaf spring 191 having its root secured to a fixed support 192, has itsfree end overlying the body 189. The cord is nipped between the free endof the leaf spring and body 189, the force of such nipping beingadjustable by the turning of a thumb screw 194 which is threaded into anoverarm 195 afiixed to support 192.

With the apparatus of the invention, in any of the forms thereofillustrated and described herein, only one of the strands, the outer,ballooned singles strand need be subjected to more than moderate tensionat any time, either in the forming or the coiling of the cord; the outerstrand is subjected to a fairly high tension in the balloon for only avery short time. The plying spindles of the invention, as aboveexplained, immediately permit such strand to assume a substantiallyrelaxed low tension condition, in advance of the plying point. Thusthere is no deterioration in the properties of the cord such as occurwhen strands are plied under high tension and/or are maintained coiledunder substantial tension for extended periods of time.

Although a limited number of embodiments of the invention have beenillustrated in the accompanying drawings and described in the foregoingspecification, it is to be especially understood that various changes inaddition to those above described, such as in the relative dimensions ofthe parts, materials used, and the like, as well as the suggested mannerof use of the apparatus of the invention, may be made therein withoutdeparting from the spirit and scope of the invention as will now beapparent to those skilled in the art.

What is claimed is:

1. Mechanism for twisting together two strands so as to form a two-plystrand, comprising a source of supply of a first strand anda supportcarrying a let-off strand package for a second strand, a rotatable shaftoperable to rotate a loop of the first strand about the let-0E packageand also to ply the two strands together at a plying point, a firstmeans for feeding the first strand into the outer end of the loop, asecond means engaging the first strand as it rotates in the loop forfeeding the first strand at substantially constant speed toward theplying point, the plying point being located adjacent the inner end ofthe loop, the second feeding means engaging the first strand in advanceof the plying point, a third means for feeding the plied strand undertension away from the plying point, strand tensioning and retardingmeans engaging the second strand at a zone in advance of the plyingpoint for subjecting the second strand to substantially constanttension, and means for conducting the second strand from the strandtensioning and retarding means to the plying point under substantiallythe tension imposed on the second strand by the strand tensioning andretarding means.

2. Mechanism as claimed in claim 1, wherein the second feeding meansengages the first strand adjacent the plying point, and wherein thethird means, for feeding the plied strand under tension away from theplying point, subject the plied strand to a tension which isapproximately twice the tension which the strand tensioning andretarding means imposes upon the second strand in the run thereofextending from said tensioning and retarding means to the plying point,and comprising means for conducting the first strand from the secondmeans to the plying point without the imposition of substantial addedtension on the first strand as it approaches the plying point, wherebythe plied strand contains approximately equal lengths of the first andsecond strands.

3. Mechanism as claimed in claim 2, wherein the first and second strandsare presented to the plying point under equal tensions, and the thirdmeans subjects the plied strand to a tension which is twice the tensionunder which each of the first and second strands is presented to theplying point.

4. Mechanism as claimed in claim 1, wherein said two strands aresubstantially inextensible under the tensions encountered in the plyingoperation and are substantially identical, and wherein the secondfeeding means feeds the first strand at a speed which exceeds the speedof feeding of the plied strand away from the plying point by the thirdfeeding means, whereby to compensate for the decrease in the effectivelength of the first strand in the plied strand caused by the twisting ofthe two strands together.

5. Mechanism as claimed in claim 1, wherein the third means, for feedingthe plied strand under tension away from the plying point, feeds theplied strand at substantially constant speed.

6. Mechanism as claimed in claim 5, wherein said two strands aresubstantially inextensible under the tensions encountered in the plyingoperation and are substantially identical, and wherein the secondfeeding means feeds the first strand at a speed which exceeds the speedof feeding of the plied strand by the third feeding means,

whereby to compensate for the decrease in the effective length of thefirst strand in the plied strand caused by the twisting of the twostrands together.

7. Mechanism as claimed in claim 1, comprising means mounting the secondfeeding means for rotation as a whole with the loop about the axis ofrotation of the loop.

8. Mechanism as claimed in claim 7, wherein the second feeding means ismounted upon the said shaft.

9. Mechanism as claimed in claim 8, comprising a flyer mounted upon saidshaft for generating said loop of the first strand, said second feedingmeans being mounted upon said flyer.

10. Mechanism as claimed in claim 7, comprising a first guide coaxial ofand remote from the shaft for guiding the plied strand away from theplying point, a flyer engaging the rotating first strand, the flyerbeing located nearer to the first guide than to the loop generatingportion of the shaft, said second feeding means being mounted upon saidflyer.

11. Mechanism as claimed in claim 10, comprising a further guide meansmounted upon the flyer for conducting the second strand from its let-offpackage and thence into contact with the first strand at the plyingpoint.

12. Mechanism as claimed in claim 10, wherein the shaft is hollow, andcomprising a storage wheel on the shaft, means for feeding the firststrand under tension into the outer end of the shaft, around the storagewheel, and thence into the loop, the first strand leaving the loopproper by way of the second feeding means on the flyer and thentravelling to the plying point at which it meets the second strand.

13. A method of twisting together two strands so as to form a two-plystrand, comprising rotating a loop of a first strand about a let-offpackage for a second strand and also plying the two strands together ata plying point, feeding the first strand into the outer end of the loop,engaging the first strand as it rotates in the loop with a feeding meanslying adjacent the inner end of the loop and in advance of the plyingpoint, feeding the first strand by said feeding means at substantiallyconstant speed toward the plying point, feeding the plied strand undertension away from the plying point, engaging the second strand at a zonein advance of the plying point by a strand tensioning and retardingmeans which subjects such strand to substantially constant tension, andconducting the second strand from the strand tensioning and retardingmeans to the plying point under substantially the tension imposed on thesecond strand by the strand tensioning and retarding means. a

14. A method as claimed in claim 13, comprising engaging the firststrand as it rotates in said loop by the said feeding means adjacent theplying point, conducting the first strand from the said feeding meanstherefor to the plying point without the imposition of substantial addedtension on the first strand as it approaches the plying point, andfeeding the plied strand away from the plying point under a tensionwhich approximates twice the tension to which the second strand issubjected immediately in advance of and at the plying point.

15. A method as claimed in claim 14, comprising presenting the first andsecond strands to the plying point under equal tensions, and withdrawingthe plied strand from the plying point under a tension which is twicethe tension under which each of the first and second strands ispresented to the plying point.

16. A method as claimed in claim 13, wherein said two strands aresubstantially inextensible under the tensions encountered in the plyingoperation and are substantially identical, and wherein the speed offeeding of the first strand by said feeding means exceeds the speed offeeding of the plied strand away from the plying point, whereby tocompensate for the decrease in the effective length of the first strandin the plied strand caused by the twisting of the two strands together.

17. A method as claimed in claim 16, comprising feeding the plied strandat constant speed under tension away from the plying point.

18. An apparatus for forming a plurality of cords simultaneously andwinding them on a common beam, comprising a plurality of similar cordforming spindles of the plywrapping type, each of said spindlescomprising a source of supply of a first strand and a support carrying alet-01f strand package for a second strand, a rotatable shaft operableto rotate a loop of the first strand about the let-off package and alsoto ply the two strands together at a plying point, a first means forfeeding the first strand into the outer end of the loop, a second meansengaging the first strand as it rotates in the loop for feeding thefirst strand at substantially constant speed toward the plying point,the plying point being located adjacent the inner end of the loop, thesecond feeding means engaging the first strand in advance of the plyingpoint, strand tensioning and retarding means engaging the second strandat a zone in advance of the plying point for subjecting the secondstrand to substantially constant tension, and means for conducting thesecond strand from the strand tensioning and retarding means to theplying point under substantially the tension imposed on the secondstrand by the strand tensioning and retarding means, means for gatheringthe cords formed by the spindles and conducting them away from thespindles in parallel spaced relationship to form a warp-like sheet, acommon take-up beam for the warp-like sheet, said take-up beamconstituting means for feeding the cords under tension away from theplying points of the respective spindles, and means for driving thetake-up beam at a substantially constant surface speed which isappreciably less than the strand feeding speed of the second feedingmeans.

19. An apparatus as claimed in claim 18, wherein the second feedingmeans of each of said spindles is driven at a strand feeding speed whichis higher than the surface speed of the take-up beam in an amountsufiicient to compensate for the decrease in the effective length of thefirst strand in the plied strand caused by the twisting of the twostrands together.

20. An apparatus as claimed in claim 19, wherein the means for gatheringand conducting the cords leads the cords to the take-up beam undersubstantially the tension under which the cords are withdrawn from therespective plying points of the respective spindles.

21. An apparatus as claimed in claim 19, comprising means engaging andadditionally tensioning the cords between the respective spindles andthe take-up beam.

References Cited UNITED STATES PATENTS 2,503,242 4/1950 Clarkson 5712,811,012 10/1957 Klein 57-5836 X 2,871,648 2/1959 Vibber 5758.362,914,903 12/1959 Klein et al. 57-58.36 X 2,961,824 11/1960 Klein57-5836 2,986,865 6/1961 Clarkson 57-583 3,153,893 10/1964 Vibber 5758.3

FRANK J. COHEN, Primary Examiner.

D. WATKINS, Assistant Examiner.

1. MECHANISM FOR TWISTING TOGETHER TWO STRANDS SO AS TO FORM A TWO-PLYSTRAND, COMPRISING A SOURCE OF SUPPLY OF A FIRST STRAND AND A SUPPORTCARRYING A LET-OFF STRAND PACKAGE FOR A SECOND STRAND, A ROTATABLE SHAFTOPERABLE TO RATATE A LOOP OF THE FIRST STRAND ABOUT THE LET-OFF PACKAGEAND ALSO TO PLY THE TWO STRANDS TOGETHER AT A PLYING POINT, A FIRSTMEANS FOR FEEDING THE FIRST STRAND INTO THE OUTER END OF THE LOOP, ASECOND MEANS ENGAGING THE FIRST STRAND AS IT ROTATES IN THE LOOP FORFEEDING THE FIRST STRAND AT SUBSTANTIALLY CONSTANT SPEED TOWARD THEPLYING POINT, THE PLYING POINT BEING LOCATED ADJACENT THE INNER END OFTHE LOOP, THE SECOND FEEDING MEANS ENGAGING THE FIRST STRAND IN ADVANCEOF THE PLYING POINT, A THIRD MEANS FOR FEEDING THE PLIED STRAND UNDERTENSION AWAY FROM THE PLYING POINT, STRAND TENSIONING AND RETARDINGMEANS ENGAGING THE SECOND STRAND AT A ZONE IN ADVANCE OF THE PLYINGPOINT FOR SUBJECTING THE SECOND STRAND TO SUBSTANTIALLY CONSTANTTENSION, AND MEANS FOR CONDUCTING THE SECOND STRAND FROM THE STRANDTENSIONING AND RETARDING MEANS TO THE PLYING POINT UNDER SUBSTANTIALLYTHE TENSION IMPOSED ON THE SECOND STRAND BY THE STRAND TENSIONING ANDRETARDING MEANS.
 18. AN APPARATUS FOR FORMING A PLURALITY OF CORDSSIMULTANEOUSLY AND WINDING THEM ON A COMMON BEAM, COMPRISING A PLURALITYOF SIMILAR CORD FORMING SPINDLES OF THE PLYWRAPPING TYPE, EACH OF SAIDSPINDLES COMPRISING A SOURCE OF SUPPLY OF A FIRST STRAND AN A SUPPORTCARRYING A LET-OFF STRAND PACKAGE FOR A SECOND STRAND, A ROTATABLE SHAFTOPERABLE TO ROTATE A LOOP OF THE FIRST STRAND ABOUT THE LET-OFF PACKAGEAND ALSO TO PLY THE TWO STRANDS TOGETHER AT A PLYING POINT, A FIRSTMEANS FOR FEEDING THE FIRST STRAND INTO THE OUTER END OF THE LOOP, ASECOND MEANS ENGAGING THE FIRST STRAND AS IT ROTATES IN THE LOOP FORFEEDING THE FIRST STRAND AT SUBSTANTIALLY CONSTANT SPEED TOWARD THEPLYING POINT, THE PLYING POINT BEING LOCATED ADJACENT THE INNER END OFTHE LOOP, THE SECOND FEEDING MEANS ENGAGING THE FIRST STRAND IN ADVANCEOF THE PLYING POINT, STRAND TENSIONING AND RETARDING MEANS ENGAGING THESECOND STRAND AT A ZONE IN ADVANCE OF THE PLYING POINT FOR SUBJECTINGTHE SECOND STRAND TO SUBSTANTIALLY CONSTANT TENSION, AND MEANS FORCONDUCTING THE SECOND STRAND FROM THE STRAND TENSIONING AND RETARDINGMEANS TO THE PLYING POINT UNDER SUNSTANTIALLY THE TENSION IMPOSED ON THESECOND STRAND BY THE STRAND TENSIONING AND RETARDING MEANS, MEANS FORGATHERING THE CORDS FORMED BY THE SPINDLES AND CONDUCTING THEM AWAY FROMTHE SPINDLES IN PARALLEL SPACED RELATIONSHIP TO FORM A WARP-LIKE SHEET,A COMMON TAKE-UP BEAM FOR THE WARP-LIKE SHEET, SAID TAKE-UP BEAMCONSTITUTING MEANS FOR FEEDING THE CORDS UNDER TENSION AWAY FROM THEPLYING POINTS OF THE RESPECTIVE SPINDLES, AND MEANS FOR DRIVING THETAKE-UP BEAM AT A SUBSTANTIALLY CONSTANT SURFACE SPEED WHICH ISAPPRECIABLY LESS THAN THE STRAND FEEDING SPEED OF THE SECOND FEEDINGMEANS.